#include<stdio.h>
#include<string.h>
void sort(char* str) 
{
    int start = 0;
    int end = strlen(str) - 1;

    while (start < end) {
        char temp = str[start];
        str[start] = str[end];
        str[end] = temp;
        start++;
        end--;
    }
}
int main()
{
	char s1[100],s2[100];
	int i;
	scanf("%s %s",s1,s2);
	sort(s1);
	sort(s2);
	int len1=strlen(s1),len2=strlen(s2);
	for(i=0;i<len2;i++)
	{
	    s1[len1+i]=s2[i]; 
	}
	s1[len1+len2]='\0';
	printf("%s",s1);
	return 0;
} 

